Cryptology ePrint Archive: Report 2014/289

An Empirical Study and some Improvements of the MiniMac Protocol for Secure Computation

Ivan Damgaard and Rasmus Lauritsen, and Tomas Toft

Abstract: Recent developments in Multi-party Computation (MPC) has resulted in very efficient protocols for dishonest majority in the pre- processing model. In particular, two very promising protocols for Boolean circuits have been proposed by Nielsen et al. (nicknamed TinyOT) and by Damg &#778;ard and Zakarias (nicknamed MiniMac). While TinyOT has already been implemented, we present in this paper the first implemen- tation of MiniMac, using the same platform as the existing TinyOT im- plementation. We also suggest several improvements of MiniMac, both on the protocol design and implementation level. In particular, we sug- gest a modification of MiniMac that achieves increased parallelism at no extra communication cost. This gives an asymptotic improvement of the original protocol as well as an 8-fold speed-up of our implementation. We compare the resulting protocol to TinyOT for the case of secure com- putation in parallel of a large number of AES encryptions and find that it performs better than results reported so far on TinyOT, on the same hardware.